Opening/close device and mobile phone provided with the device

ABSTRACT

A purpose of the present invention is to provide an opening/closing apparatus and a portable telephone apparatus equipped with the opening/closing apparatus capable of reducing manipulation force used when housings are expanded, and at the same time, capable of making compact. The opening/closing apparatus for expanding the housings has: a base ( 43 ) which is fixed within a rotary member ( 41 ) having a substantially hollow tube shape; a fixing holder ( 52 ) which is allowed to be moved only along an inner peripheral plane direction of the rotary member ( 41 ); a driving cam portion ( 3 A) having both a fixing cam member ( 51 ) and a first compression spring ( 31 ); a holding cam portion ( 3 B) having a lift cam member ( 53 ) which is coupled to the fixing holder ( 52 ), a slide cam member ( 44 ) which is engaged with the base ( 43 ) and can be slid along a shaft direction, and a second compression spring ( 32 ) which is elastically provided between the slide cam member ( 44 ) and the base ( 43 ); and also, a clutch portion ( 3 C) having a ball ( 55 ) which engages the rotary cam member ( 42 ), and a cam shaft ( 54 ) having a cam groove ( 54 A) engaged with the ball ( 55 ), which is slid with the slide cam member ( 44 ) in an integral form along the shaft direction.

TECHNICAL FIELD

The present invention relates to an opening/closing apparatus and aportable telephone apparatus provided with this opening/closingapparatus capable of automatically opening two housings in an one touchmanner by manipulating a button, while these two housings are coupled toeach other in a freely foldable manner.

BACKGROUND ART

Various sorts of foldable type portable telephones have been developedand used among conventional portable telephones, while these foldabletype portable telephones have upper-sided housings having telephonereceiving portions (speakers), lower-sided housings having telephonetransmitting portions (microphones), and hinge portions which rotatablycouple these upper-sided housings and lower-sided housings to eachother. Also, among these folding type portable telephones, for instance,such a folding type portable telephone is known which has a compactopening/closing apparatus as shown in FIG. 15 at a hinge portionthereof.

As indicated in this drawing, this compact opening/closing apparatus isconstituted by a rotary member 101, a rotary cam 102 which is engagedwith a fixing shaft 103 in a pivotable manner within the rotary member101, the fixing shaft 103 which is fixed within the rotary member 101, afixing cam 104 which is arranged opposite to the rotary cam 102 and thesliding operation of which is permitted only along a shaft directionwith respect to the fixing shaft 103, a twist spring 105 which givesrotating force to the rotary cam 102, a compression spring 106 whichgives meshing force to the rotary cam 102 and a cam portion locatedopposite to the fixing cam 104, and a pusher 107. In the pusher 107, acoupling shaft 107A is fixed to the fixing cam 104 in order to slide thefixing cam 104 along the shaft direction when the meshing condition ofthe above-described cam portion is released, while the coupling shaft107A is inserted into the fixing shaft 103 in a slidable manner.

In this compact opening/closing apparatus, the rotary member 101 isfixed to the upper-sided housing having the telephone receiving unit,and the fixing shaft 103 is fixed to the lower-sided housing having thetelephone transmitting unit, and also, both the upper-sided housing andthe lower-sided housing have been coupled to each other in the foldablemanner while this compact opening/closing apparatus is employed as ahinge portion. It should be noted that reference number 108 indicates afixed plate and reference number 109 shows a spacer.

As a consequence, in the compact opening/closing apparatus having such astructure, in FIG. 15, when both the upper-sided housing and thelower-sided housing are rotated to be overlapped with each other(namely, housings are closed) against twisting force of the switchspring 105, the rotary cam 102 is engaged (meshed) with the cam portionof the fixing cam 104, and thus, the portable telephone is held underfolded condition. As a result, this portable telephone can be portablein compact.

On the other hand, when the portable telephone is used, when the pusher107 is depressed via a button (not shown), since the fixing cam 104 isslid in a right direction along the shaft direction of the fixing shaft103 and thus the meshing condition of the cam portion is released, therotary member 101 is rotated via the rotary cam 102 by receiving therotating force of the twist spring 105, and therefore, the upper-sidedhousing is opened.

As previously explained, the conventional compact opening/closingapparatus is constructed as follows: That is, the portable telephone canbe folded and can be stored in compact when the portable telephone isportable, whereas the housings of the portable telephone can be expanded(opened) by manipulating the button in the one touch manner when theportable telephone is used.

On the other hand, in the conventional compact opening/closing apparatushaving the above-described structure, when the portable telephone isopened in the one touch manner, the button must be depressed against thecompressing force of the above-described compression spring. However, inorder to hold the folding condition of the portable telephone when theportable telephone is not used under usual condition, this compressionspring must have sufficiently strong locking force by which the rotatingforce of the twist spring can be suppressed.

In this case, this locking force “F” of the compression spring isexclusively determined by the following equation, namely,F=(spring force)×(meshing diameter of cam portion).

However, in the above-described opening/closing apparatus, since thecompactness thereof is required, there is a trend that the meshingdiameter necessarily becomes small. As a consequence, in order to securethe required locking force “F”, the compressing force of the compressionspring must be increased by such a value equivalent to the decreasedmeshing diameter. In connection to this fact, there is such a problemthat the more the opening/closing apparatus is made compact, the largerthe button manipulating force required to opened the housings of theportable telephone is increased, resulting in deteriorations ofoperability thereof.

The present invention is made to solve the above-described problem, andtherefore, has an object to provide an opening/closing apparatus and aportable telephone apparatus equipped with this opening/closingapparatus which can be made compact, and at the same time, is capable ofreducing manipulating force required when housings are expanded.

DISCLOSURE OF THE INVENTION

To solve the above-described problem, an opening/closing apparatus,according to the present invention, is featured by such anopening/closing apparatus for automatically releasing/opening twohousings which are coupled to each other by a hinge portion and arecapable of being opened/closed by manipulating a button, comprising:

a rotary member, having a substantially hollow tubular shape;

a base, integrally fixed within the rotary member;

a fixing holder, provided with a through hole along a center axisdirection thereof;

a driving cam portion, including:

-   -   a rotary cam member, which is engaged with the rotary member and        which is slidable only along a shaft direction;    -   a fixing cam member, which is integrally fixed to the fixing        holder and is arranged opposite to the rotary member; and    -   a first compression spring, which is elastically provided        between the rotary cam member and the base;

a holding cam portion, including:

-   -   a lift cam member, which is coupled to the fixing holder;    -   a slide cam member, which is engaged with the base, which is        slidable only along the shaft direction, and is arranged        opposite to the lift cam member; and    -   a second compression spring, which is elastically provided        between the slide cam member and the base, the elastic force of        the second compression spring is smaller than that of the first        compression spring; and

a clutch portion, including:

-   -   a ball, which is slidably held by the fixing holder along a        radial direction on a plane perpendicular to an axis and which        engages the rotary cam member at a slidable end thereof; and    -   a cam shaft, which is slidably held only along the shaft        direction by the fixing holder, which has a cam groove engaged        with the ball, and which is slid with the slide cam member in an        integral manner along the shaft direction.

In the above arrangement, the clutch is formed by the second compressionspring having the weak elastic force irrespective of the firstcompression spring having the strong spring force, which produces thedriving torque. As a result, when the portable telephone is opened, thebutton is merely pushed by stronger force than that of the secondcompression spring, so that the manipulation can be readily performed.

Also, an opening/closing apparatus of the present invention is featuredby that the rotary cam member includes an engaging portion which isengaged by the ball, and the rotary cam is constituted so as to executesuch a clutch operation that the rotary cam member is restricted and/orreleased by entering/deriving the ball into/from the cam groove of thecam shaft.

With employment of this arrangement, the clutch for turning ON/OFF thetransfer of power can be arranged with a relatively simple structure.

Also, an opening/closing apparatus of the present invention is featuredby that when both the rotary member and the lift cam member are rotated,since the cam shaft is slid via the slide cam member along the shaftdirection, the cam shaft executes such a clutch operation that therotary cam member is restricted and/or released by entering/deriving theball into/from the cam groove of the cam shaft.

With employment of this arrangement, in the arrangement recited in claim3, even in such a case that the portable telephone is opened in themanual manner, the driving torque is produced, and thus, the portabletelephone can be opened in light manipulating force.

Also, an opening/closing apparatus, according to the present invention,is featured by such an opening/closing apparatus wherein: theopening/closing apparatus is arranged by comprising:

a rotary member, having a substantially hollow tubular shape;

a base, integrally fixed within the rotary member;

a fixing holder, provided with a through hole along a shaft directionthereof;

a driving cam portion, including:

-   -   a rotary cam member, which is engaged with the rotary member and        which is slidable only along a shaft direction;    -   a first fixing cam member, which is integrally fixed to the        fixing holder and is arranged opposite to one cam face of the        rotary cam member;    -   a second fixing cam member, which is engaged with the fixing        holder, which is slidable only along the shaft direction, and        which is arranged opposite to the other cam face of the rotary        cam member; and    -   a first compression spring, which is elastically provided        between the second fixing cam member and the base;

a holding cam portion, including:

-   -   a lift cam member, which is coupled to the fixing holder;    -   a slide cam member, which is engaged with the base, which is        slidable only along the shaft direction, and is arranged        opposite to the lift cam member; and    -   a second compression spring, which is elastically provided        between the slide cam member and the holder, the elastic force        of the second compression spring is smaller than that of the        first compression spring; and

a clutch portion, including:

-   -   a ball, which is slidably held by the fixing holder along a        radial direction on a plane perpendicular to a shaft and which        engages the second fixing cam member at a slidable end thereof;        and    -   a cam shaft, which is slidably held only along the shaft        direction by the through hole of the fixing holder, which has a        cam groove engaged with the ball, and which is slid with the        slide cam member in an integral manner along the shaft        direction; and wherein:

the driving cam portion includes two sets of cam members having both thefirst fixing cam member and the rotary cam member, and both the rotarycam member and the second fixing cam member; and

the driving cam portion provides torque in a wide angle while cams to bemeshed with each other are defined as one hill respectively.

In the above arrangement, since the cams of the driving cam portionbecome one hill and can be freely arranged, the expansion angle of theportable telephone can be set to the wide angle.

Also, a portable telephone apparatus, according to the presentinvention, is featured by such a portable telephone apparatuscomprising: the opening/closing apparatus according to any one of claims1 to 4.

With employment of the above-described arrangement, it is possible torealize the portable telephone apparatus equipped with theopening/closing apparatus capable of reducing the manipulation forceused when the housings are expanded, and at the same time, capable ofmaking compact.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a plan view for indicating a portable telephone which uses acompact opening/closing apparatus according to a first embodiment of thepresent invention;

FIG. 2 is a side view for indicating the portable telephone which usesthe compact opening/closing apparatus according to the first embodimentof the present invention;

FIG. 3 is a sectional view for indicating the compact opening/closingapparatus (when housings are under close condition);

FIG. 4 represents operations of cams and the like of the compactopening/closing apparatus according to the first embodiment of thepresent invention, FIG. 4(A) shows an explanatory diagram as viewed fromthe side view, FIG. 4(B) is a front view thereof, and FIG. 4(C) is aperspective view of an end portion thereof;

FIG. 5 shows a rotary cam which is employed in the compactopening/closing apparatus according to the first embodiment of thepresent invention, FIG. 5(A) is a front view, FIG. 5(B) is a side view,taken along an arrow V-B in FIG. 5(A), and FIG. 5(C) is a side view,taken along an arrow V-C in FIG. 5(A);

FIG. 6 shows a slide cam which is employed in the compactopening/closing apparatus according to the first embodiment of thepresent invention, FIG. 6(A) is a front view, FIG. 6(B) is a side view,taken along an arrow VI-B in FIG. 6(A), and FIG. 6(C) is a side view,taken along an arrow VI-C in FIG. 6(A);

FIG. 7 shows a fixing cam which is employed in the compactopening/closing apparatus according to the first embodiment of thepresent invention, FIG. 7(A) is a perspective view, FIG. 7(B) is a sideview, taken along an arrow VII-B in FIG. 7(A), and FIG. 7(C) is a sideview, taken along an arrow VII-C in FIG. 7(A);

FIG. 8 shows a lift cam which is employed in the compact opening/closingapparatus according to the first embodiment of the present invention,FIG. 8(A) is a front view, FIG. 8(B) is a side view, taken along anarrow VIII-B in FIG. 8(A), and FIG. 8(C) is a side view, taken along anarrow VIII-C in FIG. 8(A);

FIG. 9 is a sectional view for indicating an opening operation of thehousings (under such a condition that button is pushed) in the compactopening/closing apparatus according to the first embodiment of thepresent invention;

FIG. 10 is an explanatory diagram for indicating an opening operation ofthe housings (under such a condition that button is pushed) in thecompact opening/closing apparatus according to the first embodiment ofthe present invention;

FIG. 11(A) and FIG. 11(B) are a torque characteristic diagram and a camcurve diagram as to the compact opening/closing apparatus according tothe first embodiment of the present invention, respectively;

FIG. 12 is a sectional view for representing an opening/closingapparatus according to a second embodiment of the present invention;

FIG. 13 is an explanatory diagram for indicating a closing operation ofthe housings in the compact opening/closing apparatus according to thesecond embodiment of the present invention;

FIG. 14 is an explanatory diagram for indicating an opening operation ofthe housings (under such a condition that button is pushed) in thecompact opening/closing apparatus according to the second embodiment ofthe present invention; and

FIG. 15 is a sectional view for representing the conventionalopening/closing apparatus.

It should be noted that in the drawings, reference numeral 1 shows anupper-sided (telephone receiving unit side) housing; reference numeral 2shows a lower-sided (telephone transmitting unit side) housing;reference numeral 3 represents a compact opening/closing apparatus;reference numerals 3A and 6A show driving cam portions; referencenumerals 3B and 6B indicate holding cam portions; reference numerals 3Cand 6C represent clutch portions; reference numeral 31 indicates a firstcompression spring; reference numeral 32 shows a second compressionspring; reference numeral 41 indicates a rotary member; referencenumeral 42 and 61 show rotary cam members (drive-purpose cam); referencenumeral 42A shows a concave-shaped inclined cam; reference numeral 42Brepresents an engaging plane; reference numeral 43 is a base; referencenumeral 44 indicates a slide cam member (hold-purpose cam); referencenumeral 44A shows a convex-shaped cam; reference numerals 51 and 62 showfixing cam members (drive-purpose cams); reference numeral 51A indicatesan inclined cam; reference numeral 51B shows a flat plane; referencenumeral 52 indicates a fixing holder; reference numeral 52B indicates anengaging hole; reference numeral 52C represents a flat plane; referencenumeral 53 denotes a lift cam member (hold-purpose cam); referencenumeral 53A shows a concave-shaped cam; reference numeral 53B representsa D-cut groove; reference numeral 54 shows a cam shaft; referencenumeral indicates a cam groove (clutch portion); reference numeral 55shows a ball (steel ball) (clutch portion); and reference numeral 6indicates an opening/closing apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring now to the accompanying drawings, embodiments of the presentinvention will be described in detail.

First Embodiment

FIG. 1 and FIG. 2 show a portable telephone having a compactopening/closing apparatus according to one embodiment of the presentinvention. This portable telephone includes a housing (will be referredto “upper-sided housing” hereinafter) 1 having a receiver (receivingunit) 11, another housing (will be referred to as “lower-sided housing”hereinafter) 2 having both a speaker (transmitting unit) 21 and a keyunit 22, and a compact opening/closing apparatus 3. The compactopening/closing apparatus 3 constitutes a hinge portion which couplesthe upper-sided housing 1 to the lower-sided housing 2 in a freelyrotatable manner.

The upper-sided housing 1 has a display unit 12 and the like in additionto the receiver (receiving unit) 11. In the case that the portabletelephone is used, a button (not shown) of the opening/closing apparatus3 which constitutes the coupling portion is depressed so as to releasethe overlapping condition of the upper-sided housing 1 with respect tothe lower-sided housing 2.

The lower-sided housing 2 has the key unit 22 and the like in additionto the speaker (transmitting unit) 21.

As shown in FIG. 3 and FIG. 4, the compact opening/closing apparatus 3is provided with a driving cam portion 3A, a holding cam portion 3B, anda clutch portion 3C as a schematic structure. The driving cam portion 3Aproduces opening force of the housings. The holding cam portion 3B holdsa closed attitude and an opened attitude. The clutch portion 3C turnsON/OFF meshing conditions of one pair of cams which are contacted toeach other under pressure.

It should be understood that the compact opening/closing apparatus 3according to the first embodiment of the present invention is arrangedin such a manner that one pair of drive-purpose cams have been formed atsymmetrical positions of 180 degrees on both a fixing cam member 51 anda rotary cam member 42 (these cam members will be explained later) ofthe drive cam portion 3A, and furthermore, angles (rotary angles ofrotary member) which produce torque become approximately 0 degree to 150degrees, since operation angles of the cams are restricted only by teethwidths of the cams.

As will be explained later, while this driving cam portion has one pairof drive-purpose cams and a first compression spring 31, this drivingcam portion 3A is arranged by that meshing rotation force generated bythis first compression spring 31 is used as a power source of openingforce for the housings. One pair of drive-purpose cams are constitutedby both a rotary cam member 42 and a fixing cam member 51, and areengaged with each other at one place.

As will be explained later, while the holding cam portion 3B has onepair of hold-purpose cams and a second compression spring 32, thisholding cam portion 3B applies pressure contact force in such a mannerthat the holding cam portion 3B applies elastic force so as to holdmutual meshing conditions. One pair of the hold-purpose cams areconstituted by a slide cam member 44 and a lift cam member 53, which areseparately provided with one pair of the above-described drive-purposecams on the side of the driving cam portion 3A.

While the clutch portion 3C has a cam shaft 54, and a ball (steel ball)55, this clutch portion 3C is arranged as follows: That is, the clutchportion 3C releases a meshing condition of the hold-purpose cams incooperation with a falling operation of the ball 55 into a cam groove54A of the cam groove 54A of the cam shaft 54 so as to permit an openingoperation of the housings. The cam shaft 54 penetrates through a centerof the hold-purpose cam of the holding cam portion 3B, and can be freelyslid along a shaft direction. The ball 55 is followed to the slideoperation of this cam shaft 54, and thus, is entered/derived into/fromthe cam groove 54A.

Next, a detailed description is made of the compact opening/closingapparatus 3 provided in the portable telephone, according to the firstembodiment with reference to FIG. 3 to FIG. 8.

As indicated in FIG. 3 and FIG. 4, the compact opening/closing apparatus3 has a rotary member 41 and a fixing cam member 51. The rotary member41 is fixed/coupled on the side of the upper-sided housing 1 in such amanner that the rotary member 41 is integrally rotated with theupper-sided housing 1. The fixing cam member 51 is similarlyfixed/coupled on the side of the lower-sided housing 2 in such a mannerthat the fixing cam member 51 is integrally rotated with the lower-sidedhousing 2.

Among these members, the rotary member 41 is formed in a hollowsubstantially cylindrical shape. A rotary cam member 42 is engaged withan inner peripheral plane of the rotary member 41 in such a manner thatthe rotary cam member 42 can be slid only the shaft direction (forexample, serration engagement may be alternatively employed). A base 43is fixed (coupled) to one edge portion of the rotary member 41 in anintegral manner.

The rotary cam member 42 is formed in a substantially cylindrical shape,while a fixing holder 52 (will be explained later) penetrates through acenter portion of the rotary cam member 42. The rotary cam member 42 isfreely pivotable along a circumferential direction with respect to thisfixing holder 52, and also, is slidably provided along a shaft directionof a cam shaft 54 (will be discussed later) which penetrates through thecenter portion of this fixing holder 52. Then, as shown in FIG. 4 andFIG. 5, the rotary cam member 42 has one pair of concave-shaped inclinedcams 42A at one end thereof, and also, has an engaging plane 42B (referto FIG. 3 and FIG. 5) on an inner peripheral wall plane thereof. Onepair of these concave-shaped inclined cams 42A are arranged opposite toeach other in such a manner that these concave-shaped inclined cams 42Aare engaged with the above-described inclined cam 51A. The slidingoperation of the engage plane 42B along the shaft direction is fitted bythe ball (steel ball) 55 which will be discussed later.

The base 43 has a substantially cylindrical shape with a claw. Since theslide cam member 44 is engaged (otherwise, may be alternativelyserration-engaged) with an inner peripheral plane of this base 43 in aD-cut shape in such a manner that this base 43 can be slid along theshaft direction, this base 43 and the slide cam member 44 (will beexplained later) are rotated with the rotary member 41 in an integralmanner.

As shown in FIG. 4 and FIG. 6, the slide cam member 44 has one pair ofconvex-shaped cams 44A at one end thereof and a through hole 44B alongthe shaft direction. The one pair of the convex-shaped cams 44A arearranged at opposite positions in such a manner that one pair of theseconvex-shaped cams 44A are fitted with convex-shaped cams 53A (see FIG.8) which will be discussed later. A cam shaft 54 (will be explainedlater) penetrates the through hole 44B.

On the other hand, a fixing holder 52 is integrally coupled to thefixing cam member 51, and also, a lift cam member 53 is integrallycoupled to the fixing holder 52. Three sets of the fixing cam member 51,the fixing holder 52, and the lift cam member 53 are operated in anintegral manner.

Further, as shown in FIG. 4 and FIG. 7, this fixing cam member 51 hasone pair of inclined cams 51A at one end thereof, while the inclinedcams 51A have specific pattern shapes. One pair of the concave-shapedinclined cams 42A of the above-explained rotary cam member 42 iscontinuously meshed with the inclined cams 51A by way of the elasticforce of the first compression spring 31.

As shown in FIG. 7 and FIG. 11(B), in the inclined cam 51A, one pair ofcam curves “f(θ)” having a predetermined pattern which is formed in apoint symmetrical manner by shifting a phase by 180 degrees. Preciselyspeaking, as shown in FIG. 11(B), a closed-status holding-purposeprojection 511 and a braking-purpose projection 512 are respectivelyformed at positions which correspond to an opening angle (θ) being zerodegree, and another opening angle (θ) being 130 degrees to 150 degreeswhich is slightly in front of 180 degrees.

A through hole 51C (refer to FIG. 4(B)) is formed on the fixing cammember 51 so as to pass from one end thereof to the other end thereof.Further, a flat plane 51B (refer to FIG. 7(A) and FIG. 7(C)) is formedon an inner peripheral plane of the through hole 51C, while this flatplane 51B is engaged with a flat plane 52C formed on a portion of anouter peripheral plane of a fixing holder 52 (will be explained later).A sectional shape of the through hole 51C represents a substantiallybale shape (or substantially D shape). It should also be understood thatan outer peripheral plane side of this fixing cam member 51 is fixed onthe side of the lower-sided housing 2.

The fixing folder 52 is formed in a substantially cylinder shape with aclaw, in which a through hole 52A is formed along a shaft direction. Aspreviously explained, the outer peripheral section where the flat plane52C is formed on a portion of the outer peripheral plane represents thesubstantially bale shape (or substantially D shape). Then, in thisfixing holder 52, a cam shaft 54 is slidably inserted into the throughhole 52A along the shaft direction. Also, the ball 55 is slidablyinserted into an engaging hole 52B along a circumferential direction,and this engaging hole 52B is pierced/formed in a plane perpendicular tothis through hole 52A along a radial direction.

As indicated in FIG. 8, the lift cam member 53 has one pair ofconcave-shaped cams 53A on one end thereof, and a D-cut groove 53B isformed in the other end thereof in such a manner that the lift cammember 53 is integrally rotated with the fixing holder 52.

The cam shaft 54 is fixed by such a stopping ring 54B as shown in FIG. 3and FIG. 4 in order that the cam shaft 54 is integrally slid withrespect to the slide cam member 44 along the shaft direction. A camgroove 54A is cut/formed in an outer peripheral plane of an intermediateportion of this cam shaft 54. The ball 55 which is entered into theengaging hole 52B of the fixing holder 52 is dropped into the cam groove54A, when the button (not shown) is pushed so as to slide the cam shaft54 along a direction of an arrow “A.”

Next, operations of the above-explained compact opening/closingapparatus 3 according to the first embodiment of the present inventionwill now be described with reference to FIG. 9 to FIG. 11.

(I) Open by Manipulating the Button:

(1) In the beginning stage, when the portable telephone is folded inorder to be stored while this portable telephone is not under operationin the normal state, as shown in FIG. 3, the ball 55 is being engagedand abuts against the engaging plane 42B. Since the ball 55 impedesmeshing operation between the fixing cam member 51 and the rotary cammember 42, opening force is not produced. At this time, as representedin FIG. 4(A), both the inclined plane of the concave-shaped cam 53A ofthe lift cam member 53 and the inclined plane of the convex-shaped cam44A of the slide cam member 44 hold the meshing condition by way of thesecond compression spring due to the elastic force to be exerted along aleft direction (namely, direction opposite to direction “A” shown inFIG. 3). As a result, the upper-sided housing and the lower-sidedhousing maintain the completely closed attitude.

(2) Next, in FIG. 3, when the button (not shown) is pushed so as toslide the cam shaft 54 along the direction of the arrow “A”, the meshingcondition between the lift cam member 53 and the slide cam member 44 isreleased as indicated in FIG. 10. Then, as shown in FIG. 9, the ball 55is dropped into the cam groove 54A. As a consequence, the restriction ofthe rotary cam member 42 made by the ball 55 on the engaging portion 42Bis released, and elastic force is exerted by the first compressionspring 31 along the left direction.

(3) As a result, torque is produced from the rotary cam member 42 whichis depressed by this elastic force along the left direction. Also, thecam face of the concave-shaped inclined cam 42A is transported in apivotable manner along the cam face of the convex-shaped inclined cam51A of the fixing cam member 51 in order to release the depressionforce.

(4) Accordingly, in FIG. 9, the rotary cam member 42 is slid along theleft direction while the rotary cam member 42 is pivotally moved alongthe outer peripheral plane of the fixing holder 52. However, as to therotary member 41 (and upper-sided housing 1 on which this rotary member41 is fixed) which causes this rotary cam member 42 to be engaged, thesliding operation along the shaft direction is blocked and the pivotableoperation along only the circumferential direction of the shaft isallowed. As a consequence, the rotary member 41 is not slid along thisshaft direction, but is pivotably moved along the same direction as thepivotable direction of the rotary cam member 42. As a result, theupper-sided housing 1 (not shown in this drawing) is pivotably moved,and therefore, such an opening operation that the housings of theportable telephone are expanded may be carried out.

(II) Open by Manual Operation:

(1) In the case that the portable telephone is opened in a manualmanner, in FIG. 3 and FIG. 4, when the slide cam member 44 is rotatedvia the rotary member 41 by the upper-sided housing 1 (not shown in thisdrawing), both the slide cam member 44 and the cam shaft 54 are slidalong the direction “A” by the lift cam member 53.

(2) Then, when this cam shaft 54 is slid, since the ball 55 is droppedinto the cam groove 54A, restriction of the rotary cam member 42 by theball 55 in the engaging portion 42B is released. Then, as shown in FIG.10, the fixing cam member 51 is meshed with the rotary cam member 42, sothat torque capable of assisting the manual expansion of the housings isproduced. As a result, the upper-sided housing 1 is pivotably moved, andthus, the opening operation is carried out by which the housings of theportable telephone are expanded.

(III) Folding Operation of Manual Operation:

(1) Conversely, in the case that the portable telephone is folded in amanual manner, as indicated in FIG. 9 and FIG. 10, when rotating forceis transferred from the upper-sided housing 1 (not shown in thisdrawing) via the rotary member 41, the rotary cam member 42 is rotated,and at the same time, is slid in the direction “A” along theconvex-shaped inclined cam 51A of the fixing cam member 51 so as torelease the restriction of the ball 55.

(2) As shown in FIG. 3, the ball 55 is pushed to be raised along the camgroove 54A by both the second compression spring 32 and the cam shaft54. As shown in FIG. 4, the rotary cam member 42 is again engaged undersuch a condition that this rotary cam member 42 is not meshed (notfitted) with the fixing cam member 51 by the ball 55, and further, boththe lift cam member 53 and the slide cam member 44 are also and againmeshed with each other (are fitted).

(3) In this case, since the depressing force of the button may be merelyequal to such a light button manipulation force irrespective of thefirst compression spring 31 having the strong elastic force whichproduces the rotating force, a so-called “one-touch opening operation”can be realized in low weight. The light button manipulation force issubstantially equal to such a manipulation force capable of enduring theweak elastic force of the second compression spring 32.

Referring now to FIG. 11, a description is made of a change in torquewhich corresponds to the opening degree “θ” of the upper-sided housing1. In this case, it should also be noted that FIG. 11(A) indicates arotation torque curve of the compact opening/closing apparatus 3according to the first embodiment. Assuming now that a cam curve of theinclined cam 51A shown in FIG. 11(B) is equal to “f(θ)”, this torque “T”may be conducted by the following formula:T=k·[df(θ)/dθ].

(I) When the upper-sided housing 1 is opened from 0 degree up to 40degrees, since the cam curve “f(θ)” corresponding to the expansionrequires large torque expansion force corresponding to, namely, theclosed status holding-purpose projection 511, rotation energy requiredto expand this upper-sided housing 1 must be applied from an externalsource.

(II) Next, when the upper-sided housing 1 is expanded from 40 degrees upto 100 degrees, a cam curve “f(θ)” corresponding to this expansion has asubstantially flat shape, and a changing rate of the inclination issimilarly set to a small changing rate, which is suppressed toapproximately a sliding resistance which is produced in the fixing cammember 51 and the rotary cam member 42. As a result, even while theopening force exerted from the external source is not required, theupper-sided housing 1 can be automatically opened by utilizing theelastic force of the first compression spring 31.

(III) Then, when the upper-sided housing 1 is expanded from 100 degreesup to approximately 130 degrees, in order to reduce shocks applied whenthe upper-sided housing 1 is fully opened (opened at angle of 180degrees), the braking-purpose projection 512 corresponding thereto isprovided. A climbing portion of this braking-purpose projection 512corresponds to this angle. Then, since a changing rate of an inclinationas to the climbing portion of this braking-purpose projection 512 is setin such a manner that this changing rate is gradually increased, thetorque expansion force is also increased.

As a result, with respect to large inertia force which is exerted to theupper-sided housing 1 under expanding operation (tried to be opened),braking force against this inertia force may be applied, and thus, abraking operation becomes effective, so that rotation (expansion) energycan be absorbed. As a consequence, shocks which are produced at thefinal stage when the upper-sided housing 1 is expanded can be canceled.

(VI) Finally, when the upper-sided housing 1 is expanded over an angleof 130 degrees, since the upper-sided housing 1 passes through a downportion of the braking-purpose projection 512, a changing rate of theinclination is also equal to zero after the upper-sided housing 1 haspassed this down portion, and the torque expansion force is no longerrequired. As previously described, if the upper-sided housing 1 isexpanded up to approximately 180 degrees and then the upper-sidedhousing 1 is completely opened, then the attitude (expansion condition)when the upper-sided housing 1 is fully opened can be directlymaintained unless such a large torque is applied which can exceed thetorque expanding torque corresponding to the above-explainedbraking-purpose projection 512.

Second Embodiment

Referring to FIG. 12 to FIG. 14, a description is made of a secondembodiment of the present invention. It should be noted that the samereference numerals shown in the first embodiment will be employed orthose for denoting the same, or similar structural elements of thissecond embodiment so as to avoid duplicated explanations thereof. FIG.12 and FIG. 13 show a portable telephone having an opening/closingapparatus 6 according to the second embodiment of the present invention.Similar to the compact opening/closing apparatus 3 of the portabletelephone according to the first embodiment, the opening/closingapparatus 6 of the portable telephone according to this secondembodiment is mainly arranged by employing a driving cam portion 6A, aholding cam portion 6B, and a clutch portion 6C. The diving cam portion6A is provided with drive-purpose cams which are meshed with each otherat two right and left places, which is different from the firstembodiment.

In this second embodiment of the present invention, assuming now thatcams which are meshed (fitted) with each other in the driving camportion 6A are one hill, and as will explained later, a lack of torqueis compensated by two sets of cams, so that a rotation angle is arrangedlarger than, or equal to 180 degrees. These two sets of cams areconstituted by both the fixing cam member 51 and the rotary cam member61, and also, both the rotary cam member 61 and the fixing cam member62.

As will be explained later, different from the first embodiment, thedriving cam portion 6A has drive-purpose cams and the first compressionspring 31. The drive-purpose cams are meshed with each other at twopositions, and are arranged by the fixing cam member 51, the rotary cammember 61, and the fixing cam member 62. The meshing rotation forcewhich is exerted by this first compression spring 31 is employed as apower source of the opening force of the upper-sided housing 1.

Similarly, in this second embodiment, an upper-sided housing 1 is fixedin such a manner that the upper-sided housing 1 is integrally rotatedwith a rotary member 41, and a lower-sided housing 2 is fixed in such away that the lower-sided housing 2 is integrally rotated with a fixingcam member 51.

The holding cam portion 6B is arranged in a similar manner to that ofthe first embodiment, and has one pair of hold-purpose cams and a secondcompression spring 32, this holding cam portion 6B applies pressurecontact force in such a manner that the holding cam portion 6B applieselastic force of the second compression spring 32 so as to hold mutualmeshing conditions with respect to these cams. Similar to the firstembodiment, one pair of the hold-purpose cams are constituted by a slidecam member 44 and a lift cam member 53.

The clutch portion 6C is constructed in a similar manner to that of thefirst embodiment. While the clutch portion 6C has a cam shaft 54, and aball (steel ball) 55, this clutch portion 6C is arranged as follows:That is, the clutch portion 6C releases a meshing condition of thehold-purpose cams in cooperation with a falling operation of the ball 55into a cam groove 54A of the cam shaft 54 so as to permit an openingoperation of the housings. The cam shaft 54 penetrates through a centerof the hold-purpose cam of the holding cam portion 6B, and can be freelyslid along a shaft direction. The ball 55 is followed to the slideoperation of this cam shaft 54, and thus, is entered/derived into/fromthe cam groove 54A.

A base 43 having the same structure as that of the first embodiment ismounted on one end side of the rotary member 41, and is engaged withthis rotary member 41 in such a manner that a rotary cam member 61 canbe slid only along the shaft direction. As a consequence, similar to thefirst embodiment, this base 43 is also rotated with the upper-sidedhousing (not shown in this drawing) and the rotary member 41 in anintegral manner.

As indicated in FIG. 13, the slide cam member 44 has the same structureas that of the first embodiment. The slide cam member 44 has one pair ofconvex-shaped cams 44A at one end (left end in FIG. 13) and a throughhole 44B along the shaft direction, as shown in FIG. 12. One pair ofthese convex-shaped cams 44A are engaged with the above-describedconvex-shaped cams 53A. A cam shaft 54 penetrates the through hole 44B.It should also be understood that similar to the first embodiment, thiscam shaft 54 is also fixed by a stopping ring 54B, or the like in such away that the cam shaft 54 is integrally slid along the shaft directionwith respect to the slide cam member 44.

A fixing cam member 51 and a fixing cam member 62 have a convex-shapedinclined cam 51 and an inclined cam 62A, which have been formed on oneend thereof over an entire circumference by 360 degrees.

Among these structural elements, similar to the first embodiment, a flatplane is formed on the fixing cam member 51, the sectional area of whichbecomes a substantially bale shape (a substantially D shape), in orderthat both a fixing holder 52 and a lift cam 53 are coupled to each otherin an integral form and are integrally rotated with the lower-sidedhousing (not shown in this drawing).

On the other hand, similar to the first embodiment, an engaging plane62B (see FIG. 12) is formed on an inner peripheral wall of the fixingcam member 62. The sliding operation along the shaft direction isretained by the ball 55 on the engaging plane 62B.

The lift cam member 53 has one pair of concave-shaped cams 53A at oneend (right end in FIG. 13). A D-cut groove is formed in the other end(left end in FIG. 13) of the lift cam member 53 in order that the otherend thereof is rotated with the fixing holder 52 in the integral form.It should also be noted that the fixing holder 52 has the same structureas that of the first embodiment.

As indicated in FIG. 13, the rotary cam member 61 has a concave-shapedinclined cam 61A which is meshed with the above-described inclined cam51A on one end thereof (left end in FIG. 13). Also, the rotary cammember 61 has a concave-shaped inclined cam 61B which is meshed with theabove-described inclined cam 62A on the other end thereof (right end inFIG. 13).

Next, operations of the above-explained compact opening/closingapparatus 6 according to the second embodiment of the present inventionwill now be described with reference to FIG. 12 to FIG. 14.

(I) Open by Manipulating the Button:

As shown in FIG. 12, when the portable telephone is folded, the ball 55is retained and abuts against the engaging plane 62B. Since the ball 55impedes meshing operation between the fixing cam member 62 and therotary cam member 61, as shown in FIG. 13, rotating force for openingthe housing is not produced. Namely, in this case, as represented inFIG. 13, both the inclined plane of the concave-shaped cam 53A of thelift cam member 53 and the inclined plane of the convex-shaped cam 44Aof the slide cam member 44 are meshed with each other (fitted to eachother) by way of compressing force of the compression spring 31, andthus, generate such a holding force by which both the upper-sidedhousing and the lower-sided housing hold completely closed attitudes.

Under this condition, as represented in FIG. 14, when the button (notshown) is pushed so as to slide the cam shaft 54 along the direction ofthe arrow “A”, the meshing condition between the lift cam member 53 andthe slide cam member 44 is released, and the ball 55 is dropped into thecam groove 54A (namely, same condition of FIG. 9 in the firstembodiment). As a result, the restriction condition of the rotary cammember 61 with respect to the engaging plane 62B is released, andmeshing force (fitting force) among three structural members, namely,the fixing cam member 51, the rotary cam member 61, and the fixing cammember 62 is produced, so that both the upper-sided housing and thelower-sided housing of the portable telephone are expanded.

(II) Open by Manual Operation:

Also, in the case that the upper-sided housing 1 of the portabletelephone is expanded from such a condition that the housings are closedas represented in FIG. 12 and FIG. 13 in the manual operation, if theslide cam member 44 is rotated via the rotary member 41 by the rotationoperation of this upper-sided housing 1, then the cam shaft 54 is slidalong the direction “A” by the lift cam member 53.

Then, in FIG. 12, when this cam shaft 54 is slid, since the ball 55 isdropped into the cam groove 54A, restriction of the fixing cam member 62by the ball 55 in the engaging portion 62B is released. As a result, asindicated in FIG. 14, the fixing cam member 51 is meshed with the rotarycam member 41, and also, the rotary cam member 61 is meshed with thefixing cam member 62 (fitted to each other), so that torque capable ofassisting the expansion by the manual manner is produced.

(III) Folding Operation of Manual Operation:

Conversely, in such a case that the upper-sided housing (not shown inthis drawing) of the portable telephone is manually folded from such acondition that the housing is opened as shown in FIG. 14, when rotatingforce is transferred via the rotary member 41 to the rotary cam member61 by way of a reverse rotating operation of this upper-sided housing ina sense opposite to the above-explained sense, the rotary cam member 61is rotated, and at the same time, is slid in the direction “A” along theconvex-shaped inclined cam 51A of the fixing cam member 51. Then, thefixing cam member 62 is also slid along the direction “A” by theconcave-shaped inclined cam 61B of the rotary cam member 61 so as torelease the restriction condition of the ball 55.

As a result, this ball 55 is pushed to be raised along the cam groove54A by both the compression spring 32 and the cam shaft 54. The fixingcam member 62 is again engaged on the engaging portion 62B under such acondition that this fixing cam member 62 is not meshed (not fitted) withthe rotary cam member 61 by the ball 55. On the other hand, both thelift cam member 53 and the slide cam member 44 are again meshed witheach other, as indicated in FIG. 13.

In accordance with the second embodiment, assuming now that cams whichare meshed with each other in the driving cam portion 6A are one hill,and a lack of torque is compensated by two sets of cams, so that arotation angle is arranged larger than, or equal to 180 degrees. Thesetwo sets of cams are constituted by both the fixing cam member 51 andthe rotary cam member 61, and also, both the rotary cam member 61 andthe fixing cam member 62.

While the present invention is described in detail and with reference tothe specific embodiments, it is apparent that the present invention maybe modified and changed without departing from the technical spirit andthe technical scope of the invention by those skilled in the art.

The present patent application is made based upon Japanese PatentApplication No. 2002-198634 filed on Jul. 8, 2002, and the contents ofwhich are incorporated herein as reference.

INDUSTRIAL APPLICABILITY

As previously described, in the opening/closing apparatus of the presentinvention, the clutch portion is formed by the second compression springhaving the weak elastic force irrespective of the first compressionspring having the strong spring force, which produces the drive torque.As a result, in the portable telephone equipped with thisopening/closing apparatus, when the portable telephone is expanded, thebutton is merely pushed by stronger force than that of the secondcompression spring, and the manipulation force used when the housingsare expanded can be reduced, so that the manipulation can be readilyperformed.

Also, in the portable telephone of the present invention, even in such acase that the portable telephone is expanded in the manual manner, thedriving torque is produced, and thus, the portable telephone can beopened in light manipulating force.

Also, in the portable telephone of the present invention, since the camsof the driving cam portion become one hill and can be freely arranged,the expansion angle of the portable telephone can be set to the wideangle.

1. An opening/closing apparatus for automatically releasing/opening twohousings which are coupled to each other by a hinge portion and arecapable of being opened/closed by manipulating a button, theopening/closing apparatus, comprising: a rotary member, having asubstantially hollow tubular shape; a base, integrally fixed within therotary member; a fixing holder, provided with a through hole along acenter axis direction thereof; a driving cam portion, including: arotary cam member, which is engaged with the rotary member and which isslidable only along a shaft direction; a fixing cam member, which isintegrally fixed to the fixing holder and is arranged opposite to therotary member; and a first compression spring, which is elasticallyprovided between the rotary cam member and the base; a holding camportion, including: a lift cam member, which is coupled to the fixingholder; a slide cam member, which is engaged with the base, which isslidable only along the shaft direction, and is arranged opposite to thelift cam member; and a second compression spring, which is elasticallyprovided between the slide cam member and the base, the elastic force ofthe second compression spring is smaller than that of the firstcompression spring; and a clutch portion, including: a ball, which isslidably held by the fixing holder along a radial direction on a planeperpendicular to an axis and which engages the rotary cam member at aslidable end thereof; and a cam shaft, which is slidably held only alongthe shaft direction by the fixing holder, which has a cam groove engagedwith the ball, and which is slid with the slide cam member in anintegral manner along the shaft direction.
 2. The opening/closingapparatus as set forth in claim 1 wherein: the rotary cam memberincludes a retaining portion which is retained by the ball, and therotary cam is constituted so as to execute such a clutch operation thatthe rotary cam member is restricted and/or released by entering/derivingthe ball into/from the cam groove of the cam shaft.
 3. Theopening/closing apparatus as set forth in claim 1 wherein: when both therotary member and the lift cam member are rotated, since the cam shaftis slid via the slide cam member along the shaft direction, the camshaft executes such a clutch operation that the rotary cam member isrestricted and/or released by entering/deriving the ball into/from thecam groove of the cam shaft.
 4. An opening/closing apparatus,comprising: a rotary member, having a substantially hollow tubularshape; a base, integrally fixed within the rotary member; a fixingholder, provided with a through hole along a shaft direction thereof; adriving cam portion, including: a rotary cam member, which is engagedwith the rotary member and which is slidable only along a shaftdirection; a first fixing cam member, which is integrally fixed to thefixing holder and is arranged opposite to one cam face of the rotary cammember; a second fixing cam member, which is engaged with the fixingholder, which is slidable only along the shaft direction, and which isarranged opposite to the other cam face of the rotary cam member; and afirst compression spring, which is elastically provided between thesecond fixing cam member and the base; a holding cam portion, including:a lift cam member, which is coupled to the fixing holder; a slide cammember, which is engaged with the base, which is slidable only along theshaft direction, and is arranged opposite to the lift cam member; and asecond compression spring, which is elastically provided between theslide cam member and the holder, the elastic force of the secondcompression spring is smaller than that of the first compression spring;and a clutch portion, including: a ball, which is slidably held by thefixing holder along a radial direction on a plane perpendicular to ashaft and which engages the second fixing cam member at a slidable endthereof; and a cam shaft, which is slidably held only along the shaftdirection by the through hole of the fixing holder, which has a camgroove engaged with the ball, and which is slid with the slide cammember in an integral manner along the shaft direction; and wherein: thedriving cam portion includes two sets of cam members having both thefirst fixing cam member and the rotary cam member, and both the rotarycam member and the second fixing cam member; and the driving cam portionprovides torque in a wide angle while cams to be meshed with each otherare defined as one hill respectively.
 5. A portable telephone apparatus,comprising: the opening/closing apparatus according to any one of claim1 to 4.